1. Line a large baking sheet with non-stick baking paper, using a pencil mark out a rectangle which measures 12cm x 30cm.
2. To make the pavlova, measure the egg whites into the bowl of a free standing mixer. Whisk on high speed until like cloud, gradually add the caster sugar a teaspoon at a time, still on maximum speed until the whites look like shiny, thick and stiff. Mix the cornflour and vinegar together in a tiny bowl and mix until smooth and runny. Pour into the meringue and stir until evenly mixed.
3. Fit a piping bag with a plain knozzle and fill with the mixture, twist to seal the top. Pipe along the lines of the rectangle on the paper and then along the base to give an even thickness of meringue. Pipe on top of the outer edge to build up the sides to give a basket of meringue.
4. Bake in preheated oven at 140°C/120°Fan/Gas 2, for about an hour, switch the oven off and leave in the oven until cold to dry out. Set aside to cool.
5. To serve, whisk the cream to soft peaks and stir in the liqueur, spoon into the inside of the pavlova. Slice the pear into even slices and arrange widths ways across the pavlova in alternate line. Scatter the chopped ginger over the top.
6. Chill until needed.